Expanding reamer



Feb. 17. 1925.

G. B. CHADWICK EXPANDING REAMER 2 Sheets-Sheet 1 Filed Jan. 1921 at! a Feb. 17. 1925.

G. B. CHADWICK EXPANDING REAMER 2 Sheets-Sheet 2 Filed Jan. 24, 1921 Patented Feb. 17, 1925.

UNITED TATES PATENT OFFICE.

enonen n1 CHADWICK, or ronrsmou'rn, new mmrsnmn 'EXIPANDING REAMEB.

Application filed January 24, 1921. Serial No. 439,414.

To all whom it may concern:

Be it known that l, Gnonon B. Cnanwrox, a citizen of the United States, residin at Portsmouth in the county of Rocking am and State of New Hampshire, have invented new and useful Improvements in Expanding Reamers, of which the following is a specification.

This invention relates to reamers or analogous tools having blades which are capab e of simultaneous radial adjustment to vary the elfective diameter of the tool.

The object of the invention is to provide certain improvements by which the tool may be used to aline axially spaced apertures, the wall or walls of which are to be cut by the blades, irrespective of whether such apertures have the same or diiferent diameters; by which different groups of blades or other work-engaging members may be adjusted radially independently of each other, and so located as not to weaken the threaded body portion of the tool; and by which other desirable results may be secured. To these ends, my invention consists of a reamer or analogous tool possessing certain structural and other features, as are hereinafter described and particularized in the claims.

On the accompanying drawin s,-

Figure 1 represents an expan ing reamer embodying my improvements.

Figure 2 re resents a longitudinal section through is e same.

Figures 3 and 4 respectively represent transverse sections on the lines 33, 44, of Figure 2.

Figure 5 represents one of the blades.

Figure 6 represents the same kind of reamer but with six blades at the rear and three blades at the front end of the tool.

Figures 7 and 8 represent transverse sections on the lines 77, 88, of Figure 6.

Figure 9 represents a longitudinal section of the tool in which the guide or seetional bushing members are substituted for the blades at the front end.

Figures 10 and 11 represent cross sections on the line 10l0 of Figure 9 showing different adjustments of the parts.

Figure 12 shows one of the guides or sec: tions of the bushing.

On the drawing, the integral driving mandrel or body 20 is shown as being of unusual length, and as having at its rear end a non-threaded shank 21 and an angular extremity 22 by which it may be gripped in the chuck of a handor power-operated spindle. The remainder of the body may be threaded continuously from the shank 21 to the front extremity as indicated at 26, but at 23 I have shown an enlargement which may constitute a unitary part of the body if desired.

The body is provided with two groups of radial, longitudinally-extending slots, in which separate groups of blades or other members may be res ectively located "for radial adjustment. ach group may con sist of any desired number of slots or members, but preferably one group should be in number equal to or a multiple of the other, so that the slots of one group are alined in dilferent longitudinal portions thereof with slots of the other group, for reasons to be hereinafter set forth.

In the tool shown in Figures 1 to 4, there are two groups of four slots 24, 25, but, of course, the number of slots may be increased or decreased, as may be permitted by the diameter of the body. The bottom walls of the slots 2% are at the same angle to the axis of the body and are forwardly converging as shown in Figure 2.' The slots 25 are alined with the slots 24, but are of greater width, and their rear ends overlap,-as it were,the front ends of the slots 24. In other words, a slot 24 extends from the point to to the point so, longitudinally of the body, while the alined slot 25 extends from the point 1 to point a, s0

that from y to w, the narrower slot 24 is formed in the bottom wall of the slot 25. The included angle, between the axis of the body and the bottom of each slot 25, may be equal to, but is preferably greater than, the angle betwt an said axis and the bottom of each slot 24. With the arrange ment of slots as shown, the blades or other members placed in one group of slots may be so adjusted as to extend into the transverse zones between m and y, and yet in said zone there is, to all intents and purposes, only one set of four slots. If the four slots 24 of one group were not alined with the four slots of group 25, there would be eight laterally-spaced slots in-the zone wy, and the external threads at 26 would be so mutilated or divided as to weaken them.'

In the group of slots 24, I place cutting blades 27, which fit accurately between the parallel side walls thereof, and which are wedge-shaped to lit the bottoms of the slot, so as to present their outer cutting edges 28 in parallelism to each other and to the axis of the body. The ends of each blade are beveled as at 29, 30, so that they may be engaged with the beveled end walls 31, 32, on the nuts 33, 34, which are screwed on the threaded body.

In the group of slots 25, I place removable blades or sectional guide or bushing members according to the work to be performed by the tool. For example, in Figures 1 to 4, I have shown a set of blades 35 as located in the slots 25. These, too, are wedge-shaped, but are shown as shorter than the blades 27, though this is not necessary. The beveled ends 36, 37, are engaged with the inwardly. beveled end walls 38, 3.), of nuts 40, 41, threaded on the body. The

members 35 are wider than the slots 24 but fit accurately between the parallel side walls of slots 25, so that, when they project or extend into the zone a23 they are supported by the bottom walls of the said slots from end to end. This would not be the case if the slots 24 and 25 were of the same width, for then the compression of the nut 40 would tend to bend the rear ends of the members 35 down into the deeper slots 24 and curve the outer edges of said members. The wedge-shaped members of the two sets are therefore seen to be arranged in pairs end to end within their slots.

From the foregoing description, it will be apparent that the members or blades 27 of one group may be radially adjusted to an effective diameter, less than, equal to, or greater than the effective diameter to which the group of members 35 may be adjusted. In Figure 1, for example, I have shown the reamer as operating in two bearing apertures a b in the webs 0 (Z, so that these two apertures may be reamed in axial alinement. In this case, the effective diameter of the group of blades or members 35 is less than that of the group of members 27. It is evident that in reaming a deep aperture,

the blades 27 may be adjusted so as to constitute. practically. extensions of the blades 35, being separated, as they are, only by the length of the two nuts 34. 40; or. if desired, the blades 35 may be so formed as to take roughing cuts andthose at 27 to take finishing cuts, so that, by the single reamer, the work may, by one pass of the tool, be both rough-reamed and finishedreamed.

In Fi ures 6 to 8 inclusive I have shown' a reamer like that previously described, except that the rear blades are in number a multiple of the front blades. That is, for example, there are six rear blades 27 and only three front blades 35. In this case,

every alternate slot 24 is alined with a slot 25 and extends into the bottom Wall thereof.

In Figures 9 to 12 inclusive, I have shown how sectional bushing or non-cutting guide members 42 may be substituted for the cutting blades in the slots 25. Each member 42 has a longitudinal rib or blade 43 which is wedge-shaped to fit in the slot 25 and which projects radially from said slot. The outer portion of each member consists of a cylindrical segment 44, which projects laterally beyond the rib. The ends of each member are beveled as at 45, 46, to be angaged and held in place by the nuts 40, 41. Preferably the convex outer surfaces of these members are so formed as to be concentric with a cylinder formed about the axis of the body. when they are adjusted radially outwardly to their maximum extent of movement, as shown in Figure 11. Then when they occupy any position nearer the center of the body, each engages the wall of the work at two separate lines of contact, along their outer edges. This I regard as a feature of advantage though it is not essential in every case. The members, which thus constitute a sectional bushing, are used when it is desired to ream, by the use of blades 27, a hole or aperture in axial aliuement with the hole in which the bushing members are centered by the walls thereof. Of course, the width of the segi'i'iental-portions of the men'ibers may vary as desired, as will be readily appreciated.

A tool may be supplied with both blades 35 and sectional bushing members to be interchangeably applied to the same body. as the nuts 40,- 41 fit both. In fact, the nuts 33, 34, 40, 41. may all be identical and interchangeable. They are of short axial length so as to inter-pose little space, when desired, between the two groups of blades 27, 35, or between a group of blades 27 and the sectional bushing members.

The nuts are less in outside diameter than the effective diameter of either the blades or the segmental bushing members, so that they will not engage the walls of the work.

I may call attention to the fact that, when two groups of blades are employed, and adjusted to the same working diameter, the tool may be employed for reaming a long bore or aperture, with better effect than if only one group of long blades were used, first, becaise the body may be of shorter length for a given radial adjustment of the blades, and. second, because long blades tend to yield or bend laterally and are less effective and accurate inoperation than two short alined blades, each of which ma be firmly gripped at its ends. It will be understood that, if desired, the segmental bushing members may be located in the slots 24. and blades may be located in the slots 25,

. that the blades 27 or 35 and the segmental members may be included in the term radially adjustable work-engaging members, since both perform the identical function of centering the body in the bore or aperture, the walls of which are engaged by said members, whereby the bore or aperture reamed by the blades 27 will be axially alined with the first-mentioned bore.

Having thus explained the nature of my invention and described a way of making and using the same, althou h without attempting to set forth all 0 the forms in which it ma be made or all of the modes or its use, w at I claim is 1. An expanding reamer comprising an externally threaded bod having two groups of longitudinal slots 0 gradually increasing de th formed therein, the slots of one group being wider than, alined with, and with their higher ends overlapping the lower ends of the slots in the other oup, groups of wedge-shaped members fitting in said groups of slots, and nuts on the threaded body engagin said members for adjusting and securing t 1c respective groups of members in adjusted positions.

2. An expanding reamer comprising an externally threaded body having two groups of longitudinal slots of gradually increasing de th formed therein, the slots of one group eing wider than, alined with, and with their higher ends overlapping the lower ends of the slots in the other group,

, groups of wedge-shaped members fitting in said cups of slots and two pairs of nuts on said threaded body for engaging and ad- 'usting'said groups of work-engaging memers.

3. An expanding reamer comprising an externally threaded body, a plurality of radially adjustable blades thereon, and centering means for said body and blades, comprisin a group of radially adjustable segmenta members having tapering ribs extending therefrom and 'slidin ly seated in complemental longitudinal s ots in said body, said members having beveled ends, and nuts on said body having internally tapered ends engaging the tapered ends of said members.

4:. An expanding reamer comprising a body portion having two groups of longitudinal slots of gradually increasing depth formed therein, the slots of one group being wider than, alined with, and having their higher ends overlapping the lower ends of the slots in the other group, groups of of ots, and means for adjusting said wedge-shaped members axially of said body portion.

5. An expanding reamer comprising a body portion having longitudinally arranged tapering slots therein, and groups of wedge-shaped members arranged in pairs end to end in said slots and adjustable longitudinally therein through different portions of the lengths of said slots, the lengths through which the members of one group are adjustable overlapping the lengths through which the members of the other groups are adjustable.

6. An expanding reamer comprising a body portion having longitudinally arranged tapering slots therein, groups of wedge-shaped members arranged in pairs end to end in said slots and adjustable longitudinally therein through different portions of the lengths of said slots, the lengths through which the members of one group are adjustable overlapping the lengths through which the members of the other group are adjustable and means for adjusting said members.

7. An expanding reamer comprising a body portion having longitudinally arranged tapering slots therein, groups of wedge-shaped members arranged in pairs end to end in said slots and adjustable longitudinally therein through different porwed e-shaped members fitting in said groups tions of the lengths of said slots, the lengths of another group, groups of wedge-shaped members fitted in said groups of slots, and means for adjustingsaid members axially of said body portion.

9. An expanding reamer comprising a body portion having in different lengthwise portions thereof groups of longitudinal slots of-gradually increasing depth the adjacent ends of said slots extending past each other, and groups of wedge-shaped members ltlnigitudinally adjustable in said groups of s ots.

10. An expanding reamer comprising a body portion having longitudinally arranged tapering slots therein, and groups of wedge-shaped members arranged in pairs end to end in said slots and independently adjustable longitudinally therein through different portions of the lengths of said slots, the lengths through which the members of one group are adjustable overlapping the lengths through which the members of the other groups are adjustable.

11. An expanding reamer comprising a body portion having longitudlnally arranged tapering slots therein. groups of wedge-shaped members arranged in pairs end to end in said slots and adjustable.

longitudinally therein through different portions of the lengths of said slots. the lengths through which the members of one group are adjustable overlapping the lengths through which the members of the other group are adjustable. and independent means for adjusting each group of members.

12. An expanding reamer comprising a body portion having groups of longitudinal slots of gradually increasing depth therein, the higher ends of the slots of one group projecting past the lower ends of the slots ofanother group, groups of Wedge-shaped members fitted in said groups of slots, and means for independently adjusting said members axially of said body portion.

13. An expanding reamer comprising a body portion having in different lengthwise portions thereof groups of longitudinal slots of gradually increasing depth the adjacent ends of said slots extending past each other, and groups of Wedgeshaped members independently longitudinally adjustable in said groups of slots.

In testm'iony whereof I have affixed my signature.

GEORGE B. CHADWIC K. 

